• TRAVERSABILITY OF BLOCK LINE GRAPHS

V. R. KULLI*

Abstract

The black line graph Bl(G) of a graph G is the graph whose point set is the union of the set of points, lines and blocks of G, with two points adjacent if one corresponds to a point of G and other to a line incident with it or one corresponds to a block B of G and other to a point v of G and v is in B. In this paper, we establish a necessary and sufficient condition for the block line graph of a connected graph to be eulerian. Also we obtain a characterization of graphs whose block line graphs are hamiltonian.